


Negative Spaces

by Cunninglinguist



Category: The Umbrella Academy (TV)
Genre: Anal Sex, Angst, Angst and Porn, Bisexual Diego Hargreeves, Blood, Breathplay, Bruises, But Only A Little I Swear, Canon-Typical Violence, Choking, Declarations Of Love, Drug Addict Klaus Hargreeves, Dysfunctional Family, Emotional Manipulation, Face-Fucking, Feels, Implied/Referenced Drug Use, Kissing, Knifeplay, Knives, M/M, Oral Sex, Porn with Feelings, Pre-Canon, Referenced Diego/Eudora, Rough Sex, Sibling Incest, Smut
Language: English
Status: Completed
Published: 2019-03-05
Updated: 2019-03-05
Packaged: 2019-11-12 12:16:00
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,326
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18010751
Author URL: https://archiveofourown.org/users/Cunninglinguist/pseuds/Cunninglinguist
Summary: Diego never knows what to expect when it comes to Klaus, only that he probably shouldn't expect much. That doesn't stop him from hoping for the best, anyway.





	Negative Spaces

**Author's Note:**

> This is set at some point after Diego and Eudora break up, but before TV canon begins. I like to think it's a year or 6 months before canon, but it could be at any time. 
> 
> Self-betaed; all mistakes are on me. Enjoy!

“Twentyfortysixtyeightyhundredonetwentyonefortyone--” Diego’s breath catches. He stops counting the bills in his hand. The post-fight exhaustion evaporates from his body, and he’s _on_. The door to the boiler room isn’t ajar, but something is off--he’s been living here long enough to know. Jaw set, he wads the money up and zips it into the inner pocket of his gym shorts, then dips his hand lower to grasp the knife he always keeps strapped to his thigh. You know, just in case.

He crouches down and gently pushes the door open. Unlocked, as he’d feared. He can hear someone rustling about inside, making absolutely no effort to conceal their presence. He furrows his brow. What kind of _idiot_ …

There’s an exceptionally loud crash, followed by an even louder, “Oww!”

Ah. _That_ kind of idiot. Diego shakes his head and sheathes the knife, not sure whether to be furious, or maybe...maybe a little bit hopeful. 

He decides to try furious first, seeing as hopeful’s never really worked out so well. 

Unwilling to compromise the element of surprise, Diego stays low as he creeps into his own place. Good thing he’s had all this stealth-mode practice as an almost-cop and, more recently, a beacon of vigilante justice; clearly, it was all meant to culminate in this moment. He closes the door as quietly as he can and sneaks down the stairs. 

Sure enough, there was the gangly, unmistakable form of Klaus Hargreeves, doubled over next to Diego’s desk and holding his knee, eyes squeezed shut in pain. Dramatic even when he thought he was alone. Of course.

With a whine, Klaus releases his knee and shakes out his arms and legs. He’s in some fur-trimmed jacket that nearly swallows him whole; naturally, he’s still too thin. Diego tries not to get imaginative in wondering where he’s been all this time that he’s clearly not been eating. Klaus bends over the desk and begins frantically rummaging through Diego’s things, muttering to himself. 

Diego is close enough to make his move. He leaps out and grabs Klaus from behind, ignoring his flailing and wild shrieks as he easily spins his brother around and pins him to the wall by both skinny wrists.

“Oh hi, Diego,” rasps Klaus, tilting his head and grinning. “I’m so glad you’re home, I--”

“What the fuck are you doing here, Klaus? You high?” Diego’s torn between seeing red and worrying about the state of the man before him. He _seems_ sober, he’s not sweating or shaking, his pupils aren’t dilated…

“Actually, thirty days clean and sober, thank you very much.” Klaus points a skinny finger down. “If you’d just, uh...I’ve got the chip right there in my pocket, if you’d, uh, unhand me, I could even show it to you.”

For some reason, this incenses Diego. He lets go of Klaus’ wrists only to slam him back into the wall by his shoulders, fingers tightening in the fabric of that fucking ridiculous jacket. “I don’t see you, don’t hear a damn thing from you for months,” he says, voice low and dangerous, “and you show up here, break into my spot, go through all my stuff, and think I’m just gonna give you a pass because you’ve managed to not inject yourself with that poison for thirty days?”

Klaus grits his teeth in a pained smile. “Yeah, kinda? And technically I haven’t ‘injected myself’ with anything in over a year, I prefer pills these days.”

“Jesus _fucking_ Christ, you’re impossible.” Diego presses his knuckles into Klaus’ shoulders, earning a pained little gasp that he likes a little more than he probably should. He leans in close. “I usually don’t go so easy on folks who break into my place. You’re lucky I didn’t pull my knives on you.”

“Ooh. Well, now I kinda wish you did.” Klaus bites his bottom lip, and the way he’s looking at Diego now is the kiss of death, all bedroom eyes and suggestion. Diego wishes he could fight it off, he knows it will only end in pain--for him, for both of them--but he can feel his resolve splintering with each second he endures under the scrutiny of those pretty green eyes.

He reaches down, lightning-quick, and pulls out the knife Klaus didn’t realize he had. He holds the blade against that milk-white neck while his other hand keeps pressure on Klaus’ shoulder, trapping him. Klaus’ breath hitches. 

“You like that?” He presses just so. A gorgeous pinprick of red blooms where sharp edges meet delicate skin. Klaus gasps, then leans into it, forcing it slightly deeper, and Diego can’t take his eyes off of the sight of the blood dripping down his blade, down Klaus’ throat. 

“Mmm, god. You know I do.” 

_Jesus._ Diego decides to try getting a straight answer out of his brother one more time before he succumbs entirely to him. His eyes search Klaus’ face. “Why are you here?”

“I missed you.” The answer is instantaneous, like Klaus knew what he was going to ask. Then a cold, clammy hand closes tightly on Diego’s bare forearm. “I missed you so much.”

Something deep inside Diego’s chest aches. He wishes that was true. More than anything. Diego shakes his head, murmurs _no you didn’t,_ and Klaus nods to contradict him.

“I did. I do! Miss you. So much. But I knew you had someone for a while there, so…” He lets out a mournful sigh as he trails off.

“Fuck. No. We’re _not_ talking about her.” Diego glowers at Klaus, remembering how furious he’s supposed to be. “You don’t get to just waltz in and start running your mouth about shit you don’t know. You don’t know my life. You don’t know me anymore. You shouldn’t even fucking _be_ here, Klaus.”

“Well, what are you gonna do it about it, huh?” Klaus narrows his eyes and juts his chin out, challenging him. A warm trickle of his blood runs over Diego’s knuckles, and he knows he’s lost. 

Klaus bites that lower lip again, and wraps his hand around Diego’s wrist. Diego watches helplessly as he brings his hand to his lips, the knife clattering to the floor as he unfurls his fist and lets Klaus suck his bloody index finger into his mouth, heavy-lidded gaze locked on his face. 

Diego’s rational mind is screaming that none of this is real, that his brother is using him, and he tamps it down violently as he hauls Klaus towards him, lifting him by the lapels of his coat and crushing their lips together. He tastes blood and cigarettes and booze and sweat and it’s perfect, _Klaus_ is perfect, and he wants him so badly he’s willing to forget everything he knows for the most ephemeral shred of what they once had, of the people they once were.

Klaus is still unhinged and ravenous in bed--all the drugs and bad habits have done nothing to quell that--and Klaus’ tongue is in Diego’s mouth and his hands are running appreciatively over his sweat-soaked tank top, feeling the muscles in his chest, fingertips grazing his biceps, before slipping under the hem of his shirt and brushing against his abdomen.

They break apart, and Diego is certain that the naked desire in Klaus’ eyes is mirrored in his own. They tear at one another’s clothes, Klaus standing on tiptoes to yank off Diego’s shirt as Diego pushes his coat to the floor. With a breathy laugh, Klaus raises his arms overhead and lets Diego pull his crop top off, and suddenly it’s like no time has passed at all, and they’re kids again, giggling and kissing and trying to be quiet as they slip their hands into each other’s pants under Diego’s covers. 

Except they’re not kids anymore, and Klaus has fucked all of them over, has fucked _Diego_ over, enough times for the damage between them to be irreparable--or so Diego had thought. _This time might be different,_ he thinks deliriously as he slots his thigh between Klaus’ legs.

“I want you,” breathes Klaus against his lips, little hips working as he grinds against Diego’s thigh. 

Diego’s vision tunnels with lust. With a steady inhale, he picks Klaus up, hands splayed possessively on his ass, and Klaus lets out an endearing squeal and wraps his legs around Diego’s waist. He cups Diego’s face to press frantic kisses to his lips as Diego stumbles over to the bed, yanking back the curtain and tossing Klaus down onto the comforter. 

Diego’s met with expectant green eyes, so he yanks each of Klaus’ sneakers off, followed by his socks. He raises an eyebrow, and Klaus nods vigorously, so he unzips those infernally tight pants, hooks his fingers into the waistband, and slowly peels them off of long, slim legs. 

Klaus isn’t wearing any underwear, and Diego can’t resist the urge to press his face to his groin and inhale. He smells like soap and sweat and _Klaus_ , and it’s a skeleton key to all the feelings Diego’s worked so hard to bury, or to channel into fighting, and to leave unspoken. They swarm him, rushing into his chest and _burning_ , and he hides his face in Klaus’ inner thigh, overwhelmed in a way he hasn’t been in years. 

“You okay down there, baby?” Klaus is sitting up on his elbows, smiling down at Diego. 

Diego worries that he might stutter if he speaks, so he responds by opening his mouth and sucking a bruise into Klaus’ inner thigh, which coaxes a lovely groan from swollen lips. Then he bites down, so hard that Klaus convulses and lets out a cry. Good, he wants it to hurt. He knows Klaus wants it to hurt, too. 

He pulls back, loving the stark contrast of the purpling bruise against Klaus’ porcelain flesh. It’s comforting to know that, when Klaus inevitably leaves his place to get high enough to forget his own name, he’ll be forced to remember Diego every time he looks at his body. 

It’s awful, the impermanence of it all, combined with its inevitability, and the certainty that Diego knows it will happen again. Now there’s a sorrowful rage building beneath his lust that possesses him to suck and bite a matching bruise onto Klaus’ other thigh. This is a welcome development, judging by the sigh from above him, and Diego bites up his thigh like a vampire, latching on until he tastes blood and Klaus is squirming and shaking and moaning. 

“Yeah, oh god, that’s so good,” gasps Klaus, head lolling back. His cock is leaking now, the masochist, and Diego can’t stop himself from surging forward and tasting it. 

“Diego!” Klaus bows off the bed, hands flying to his own hair, pulling at messy curls as his hips stutter. 

Diego isn’t sure if hearing Klaus cry out his name so brokenly makes him want to cry or to come, but he’s certain that he needs quiet, or else he’ll say something he’ll regret. Narrowing his eyes, he crawls up Klaus’ body until his crotch is level with Klaus’ face. 

Desperate fingers tug the waistband of his shorts down, and Klaus stares innocently up at Diego as he opens his mouth. Fire flares in Diego’s gut and he stares right back at Klaus and feeds him his cock, one hand braced on the headboard.

Diego exhales loudly, barely giving Klaus any time to adjust before he thrusts deep. Klaus moans around him, like he’s the best thing he’s ever tasted, and his eyelids flutter as he takes what he’s given. Diego rolls his hips, and Klaus’ hands are on his ass, kneading and encouraging him to thrust. Diego groans at the enthusiasm, and the apparent lack of a gag reflex as he fucks Klaus’ face, roughly pushing into his throat. 

“Fuck.” It’s been so long since Diego had been with anyone, never mind someone as skilled as Klaus, and he feels that white hot pleasure shooting up his spine long before he’s ready for it. He pulls out suddenly, and Klaus gasps for air, pink tongue peeking out to lick the saliva from his lips. 

“Are you gonna fuck me now, Diego?” Klaus reaches down and squeezes his own prick, glistening with precome, and shudders. “I’m so fucking hard for you.”

“Yeah.” Diego scrambles to get out of his shorts and tosses them to the ground, leaning over his beautiful partner to rummage awkwardly next to his bed, doing his best to ignore the little kisses Klaus is pressing to his chest as he fishes out his trusty lubricant and a rogue condom.

Klaus spreads his legs eagerly and Diego wants him so badly he could punch a hole in the wall. Klaus is so pretty everywhere, even here--he slicks up his fingers and rubs the blood-hot entrance to his brother’s body, relishing every little gasp and sigh. Without asking, he slips a fingertip inside.

“Still so tight,” he breathes. He presses the heel of his hand against one of the more wicked bruises on Klaus’ inner thigh as he slides his finger deeper. 

“Holy shit.” Klaus’ mouth is slack, breath coming in pants as Diego fucks him slowly with his finger, pressing harder on the bruise with each thrust. When Klaus is trembling, he adds a second finger, and Klaus’ hand finds his erection, starting a slow stroke that must be pure torture for him. 

“Oh, _god,_ baby.” Klaus bucks up into his own hand and Diego’s fingers slip free. “No more playing, I wanna feel you.”

Diego’s just fine with that; he’s so hard he thinks he might explode. He squirts a handful of lube into his palm and greases up his cock before tearing the condom open.

“Aw.” Klaus pouts and nudges a foot against Diego’s forearm, pushing the hand holding the condom away. “Diego. I wanna _feel_ you.”

“Klaus, come on.” He raises an eyebrow, pissed that Klaus thinks he’s stupid enough to agree to that right now, with his history. “You’ve gotta be fucking kidding me.”

Klaus shakes his head wildly, curls flopping into his face. “No, no--they made me get tested at the place, and like I said, I haven’t even used needles in, like, a year. Besides, you kind of already had a little bit of my blood in your mouth, I think?” He gestures to the wound scabbing over on his neck. 

“Not gonna happen.” _Although, it might, if you actually stuck around for a while and got sober for real. We could get tested together, and then maybe I could fuck you without a condom._ Not that he's convinced that it really matters--and it probably doesn't, not at this point--but it feels good to put his foot down. Plus, Klaus is looking up at him like he can read his thoughts, so Diego forcefully turns him over and maneuvers him onto all-fours. He roughly knees his thighs wide. He breathes deeply, taking a moment to enjoy the lovely, pliant mess before him, then upturns the lube, pouring it down Klaus’ asscrack. 

A surprised little yelp issues from beneath him, and Diego can’t take it anymore. He needs this, he needs Klaus. Painful thoughts start creeping back into his mind, whispers of what will never be and what could so easily be, so he silences them by rolling on the condom and pushing into Klaus. 

Klaus lets out an unrestrained cry and arches his back exquisitely. Diego grabs his hips and yanks him back onto his length, staring down in hazy awe as he watches himself slide slowly in and out of Klaus’ tight hole. 

“Oh, _fuck_ yeah,” groans Klaus, falling to his forearms, tilting his face so Diego can see his lashes fluttering. Diego squeezes his ass, hard, before leaning over and grabbing a fistful of Klaus’ hair and _yanking_. Klaus moans brokenly, his fingers twisting desperately in the bedspread. Spurred on by this reaction to his roughness, Diego splays his hand on the base of Klaus’ head and pushes his face into the pillow. Mind static, he pulls one of Klaus’ forearms behind his back, like he means to break it, and holds him steady as he thrusts harder, deeper. 

Klaus is _loud_ , but his groans and his words are muffled by the pillow, and Diego can only deprive himself for so long. Without warning, he releases Klaus and pulls out, flipping his trembling brother onto his back and gripping his ankles to spread him wide before thrusting back in. 

“Fuck, you feel so good.” Klaus’ eyes roll back in his head and he reaches up to grab the headboard as Diego slams into him with deep, full strokes that have Klaus edging further up the mattress each time. “No one fucks me as good as you do, Diego.”

“You’re goddamn right.” Diego presses a wet kiss to Klaus’ instep before resting his ankles on his shoulders and leaning forward, folding his bendy partner nearly in two. When he moves his hips this time, Klaus’ mouth falls open and his grip tightens until his knuckles turn white. 

“That good? You like that?” Diego can feel the quivering in Klaus’ legs, the way he’s flexing and pointing his toes, the sweat sliding between their bodies...and the look of unequivocal ecstasy on Klaus’ face is to fucking die for. A delicious, maddening heat coils rapidly in Diego’s gut. 

“I do, I do, I like it so much,” gasps Klaus. When he opens his eyes, they’re wet. “I love you, Diego.”

Diego feels like he’s been simultaneously punched in the gut, the junk, and the heart. He bites his lip to keep from responding, and Klaus slides his legs down to wrap around Diego’s waist, crossing them at the ankles behind his back. His sweaty hand finds the back of Diego’s neck, pulling his face down. 

“I love you so much,” he pants directly into Diego’s ear. 

Diego groans, capitulating entirely to those magic words, and buries his face in Klaus’ neck. He eagerly laps up the sweat beading his collarbone, sucking bruises that he hopes will rival those on his thighs under his jaw. Klaus turns his head, and Diego licks his lips at the sight of the little knife wound, a thin line that’s black with congealing blood, making it look deeper and worse than it actually is. He loves that he put that there, along with all of these little hickeys and bruises and bitemarks. He loves that anyone who looks at Klaus will see that he belongs to Diego, even if they can’t see the gorgeous way their bodies move in tandem, or taste the tears of pleasure and pain that leak out of the corners of Klaus’ eyes, or hear the way he’s wailing out Diego’s name, letting the world know that he’s his, his, _his_ \--

Klaus gasps, sharp and wounded. His legs tighten around Diego’s waist. “I’m so close, oh--oh god, _Diego,_ I’m so fucking close.”

Diego pushes himself up--he has to see this. Klaus’ head is thrown back, one hand clawing at Diego’s back while the other works desperately between his legs. He knows exactly what Klaus needs to get off. 

Klaus’ eyes fly open, wet lips parted as Diego squeezes one hand around the mottled flesh of his neck. “Yeah, _mmm._ Harder.”

Diego tightens his grip, gritting his teeth. Klaus is feverishly undulating his hips, fucking himself back onto Diego as his eyelids flutter in pleasure. Lust spikes in Diego’s belly and he feels himself coming undone at the seams as he watches. “That’s it, Klaus. Come on, baby. Come on. I love you so much, you’re so fucking sexy, come on, baby.”

Everything falls apart in slow motion: Diego chokes him just a little harder, and Klaus gasps his name, _I love you, I love you,_ and goes rigid, clenching around Deigo’s cock and coming in thick spurts on his stomach. His face is open in a way that can’t be faked, torn between agony and ecstasy, and _fuck_ if he isn’t the most beautiful thing Diego has ever seen...and once he’s gone limp, Diego pulls out, rips the condom off, and sits back on his knees to furiously tug himself. 

With a sated hum, Klaus crawls over to him, back arched like some porno fantasy, and lowers his head, taking his overstimulated prick in his mouth with a moan. That’s all it takes for Diego’s vision to white out as his orgasm wracks his body, and he comes hard in Klaus’ mouth, pulling out a little to finish on his pretty face, stuttering out his name. 

Diego’s heart thunders in his chest as he leans back to steady himself on the bedspread, hating how noisy his exhales are (they’re bordering on sobs, if he’s honest) as he recovers.

“Wow.” Klaus lets out a sleepy laugh and sticks his tongue out, deliberately licking his lips to clean off the come, blinking rapidly to avoid getting any in his eye. “That was even hotter than I imagined it would be.”

Diego doesn’t answer. Instead, he stands on wobbly legs, rummaging in his closet until he finds wet wipes and antibiotic ointment. He wipes his hands and prick unceremoniously and tosses the packet to Klaus.“There’s a shower outside, in the gym. You can use it if you want. Nobody’s here.”

“As appealing as that sounds, I’m fine right here.” Klaus smiles crookedly, wincing slightly as he runs the cloth over the cut on his neck. 

“Oh.” Diego throws the ointment over. “For your neck. And, um, probably your thighs.”

“Ha! Thanks. Always such a gentleman.” 

This--the sex, the conversation, the way they fit into each other’s negative spaces--whatever this is between them, it’s so easy, and it feels so right...Diego turns away. He fills a cracked plastic cup in the sink, gulps it down, and refills it. This is all going to come to an end, and soon, if long-repeated history is anything to go on, and as much as he wants to prolong the fantasy…

Klaus yawns loudly, stretching his arms overhead and tossing a soiled wipe onto the small pile that he’s made on the floor. Diego hands him the cup of water, which he downs gratefully. He smacks his lips and lets out a long, satisfied moan. “That was spectacular. Now, why don’t you--” he scoots his skinny, naked ass to the side and pulls the covers back “--join me?”

 _Hell._ A smile pulls at Diego’s lips. Why not indulge, just a little longer? He climbs in and opens his arms. Klaus’ head rests on his chest; his body fits perfectly next to Diego’s. Diego clears his throat. “So, are you really gonna stay this time?”

Klaus shifts and gives him warm, starry eyes. “Of course I’ll stay. I mean. If you want me to.”

“You know I do.” He presses a fierce kiss to Klaus’ damp forehead. _I always want you around._

“Mmm.” Klaus sighs contentedly, nestling into Diego’s body like he belongs there. Which he does. “I love you.” 

“I l-love you, too.” Diego bites his lip the moment the words are out of his mouth, trying to ignore the self-loathing that’s welling within him at his own fucking stupidity. It’s easy when Klaus is there, real and warm, against him, to pretend that this time Klaus actually means what he said, that he does love Diego enough to stay. Enough to stop looking for answers at the bottom of a baggie, to let Diego help him, let him take care of him the way he’s wanted to since they were boys. 

Maybe it would all be real tomorrow morning. Who knows? Stranger things have certainly happened. Head swimming with visions of magical green eyes and red lips, Diego drifts off into a deep but dreamless sleep. 

He wakes to sunlight streaming through his shitty little window and a cold bed. He’s not surprised, but he wishes that he were. Klaus’ clothes are gone; the only evidence that he was ever there is the 30 day chip that must have fallen from his jacket in his haste to get out. 

His heart cracks as he picks up his shorts from the floor and finds the inside pocket unzipped and turned out. All of his winnings are gone. Christ, he had been an idiot. He presses the heels of his hands to his eyes, hard enough to see kaleidoscopic colors, wishing the ground would just swallow him up so he could sink into oblivion. To be fair, he’d known what he was signing up for when he allowed Klaus to stay, to sink his claws into him again, to knowingly acquiesce to every trick in Klaus’ book that pushed at his buttons and made him _hope_. 

Sighing, he pulls on a pair of sweatpants and grabs the empty cup that Klaus had left next to the bed. He’d train today, bust out the police scanner at night, get real fucking merciless on some bad guys (like… _merciless_ , in a way that Eudora would likely freak out about when she saw, but Diego knew she secretly admired), and life would go on, just as it always had. 

As he heads to his cupboards to make whatever sorry excuse for coffee he has lying around, Diego notices something. On the kitchen counter is his emergency knife, dried flecks of rust-colored blood clinging to the blade. Anchored beneath it is a note, written on the back of a Post-It snatched from Diego’s fridge. In Klaus’ loopy scrawl, all it says is: _I’m sorry. I really do love you. X_

Diego crumples it in his fist and hurls his empty mug at the wall, smashing it into a million pieces. Another day, another heartbreak--and he couldn’t even say he didn’t see this one coming. 

He couldn’t even say he wouldn’t welcome it back with open arms, because he would. Always.

**Author's Note:**

> Ta-da! My first foray into the Umbrella Academy, brought to you by last night's cold medicine-fueled fugue state. If you enjoyed it, I am a total slut for comments, and I like kudos too.
> 
> I'd also like to add that, as angsty as it is, I found a lot of comfort and catharsis exploring Klaus as a drug addict before he's ready to redeem himself, when he's still got no qualms about fucking people over, even people he loves. I am excited to keep consuming (and hopefully creating) more content about this wonderfully complex, imperfect character & his many facets. 
> 
>  
> 
> I'm also on [Tumblr dot com](http://hannibalssweaters.tumblr.com/), if you're into that.


End file.
